102 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



elongated ; receptacles swollen, broad, usually united in pairs, and some- 

 times with a small margin formed 6f the unchanged frond. 



Exs. — Algae Am. Bor., Farlow, Anderson & Eaton, No. 107. 



Eastport, Maine; coast of Massachusetts; Northern Europe; Arctic 

 Ocean . 



A species apparently common north of Cape Cod, and at Eastport quite as common 

 as F. vesiculosus, for which it might be mistaken. As found with us, it is broader thau 

 the last-named species and is usually without bladders, and when these occur they 

 seem more like irregularly inflated portions of the frond than spherical cavities. The 

 receptacles contain both antheridia and oospores, the latter occupying the base and 

 the former the upper part of the conceptacle. The receptacles are broader and less 

 swollen thau in F. vesiculosus and are often in pairs, the pairs being united below. 

 The whole plant is shorter, stouter, and more foliaceous than F. vesiculosus. The spe- 

 cies as found in the Arctic regions is variable, and several forms have been described. 

 The form which occurs at Eastport comes very near the typical form. F. miclonensis 

 of De la Pylaie is probably a small form of the present. 



F. furcatus, Ag., Icon. Iued., PI. 14. 



Fronds hermaphrodite, branching very regularly dichotomous, stipi- 

 tate, one to three feet long, midrib distinct below, scarcely visible above, 

 margin narrow, rigid, entire ; bladders wanting ; receptacles flat, nar- 

 row, linear-fusiform, sometimes forking. 



Exs. — Algse Am. Bor., Farlow, Anderson & Eaton, No. 108. 



Peak's Island, Maine ; coast of Massachusetts north of Boston ; North- 

 ern Europe; Arctic Ocean; North Pacific. 



A common and beautiful species on exposed coasts north of Boston. It is found 

 lower down than F. vesiculosus, at the limit of low-water mark. The frond is narrow, 

 tough, and destitute of bladders, and the branching very regular, almost flabellate. 

 It is easily distinguished by the receptacles, which are not in the least swollen and are 

 narrow and longer than in any other species, being sometimes four inches long. The 

 color is dark. Our form corresponds perfectly to specimens from Spitzbergen. The 

 species is less A r ariable than most of the genus and is found at all seasons of the year. 



F. filiformis, Gmelin. (F. distichus, L., in Farlow's List of the Ma- 

 rine Algce of the United States.) 



Fronds hermaphrodite, three to six inches long, flabellately dichoto- 

 mous, stipitate below, midrib present but indistinct ; air-bladders want- 

 ing ; receptacles linear-oblong, swollen, borne in pairs, sometimes forking. 



In pools near high-water mark. 



Nahant, Marblehead, Mass. 



Our smallest species, found only in spring and in pools where the water is not very 

 pure. Our form is the same as No. 201 of Areschoug's Algse Scandinavicce, from Fin- 

 mark, which Agardh refers to F. filiformis. Whether F. distichus, L., is not the same as 

 F. filiformis, Gmelin, admits of doubt. The present form seems to be the F. filiformis of 

 the Flore de Terre-Neuve, mentioned under F. distichus in the Nereis Am. Bor. 



